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| Date | Mon, 3 Mar 2014 17:02:14 -0500 |
| Subject | Re: Reference |
| From | Jerry Hill <malaclypse2@gmail.com> |
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On Mon, Mar 3, 2014 at 4:51 PM, Tim Chase <python.list@tim.thechases.com> wrote:
> There are a couple use-cases I've encountered where "is" matters:
>
> 1) the most popular:
>
> if foo is None:
> do_stuff()
I know this is the one that always comes up, but honestly, I feel like
"is" doesn't matter here. That code would be just as correct if it
was written as:
if foo == None:
do_stuff()
The only time it would give you a different result from the "is"
version is if foo was bound to an object that returned True when
compared with None. And if that were the case, I'm still not
convinced that you can tell from looking at those two lines of code
which one is buggy, except for the fact that there has been 20 years
of custom saying that comparing to None with equality is wrong.
--
Jerry
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Reference "ast" <nomail@invalid.com> - 2014-03-03 10:42 +0100
Object identity (was: Reference) Ben Finney <ben+python@benfinney.id.au> - 2014-03-03 21:00 +1100
Re: Object identity (was: Reference) "ast" <nomail@invalid.com> - 2014-03-03 11:21 +0100
Re: Reference "Mark H. Harris" <harrismh777@gmail.com> - 2014-03-03 05:09 -0800
Re: Reference Grant Edwards <invalid@invalid.invalid> - 2014-03-03 14:29 +0000
Re: Reference Rustom Mody <rustompmody@gmail.com> - 2014-03-03 07:52 -0800
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-04 08:10 +1100
Re: Reference Tim Chase <python.list@tim.thechases.com> - 2014-03-03 15:24 -0600
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-04 08:31 +1100
Re: Reference Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-03-03 21:35 +0000
Re: Reference Marko Rauhamaa <marko@pacujo.net> - 2014-03-04 00:07 +0200
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-04 09:18 +1100
Re: Reference Alister <alister.ware@ntlworld.com> - 2014-03-04 11:10 +0000
Re: Reference Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-03-04 11:48 +0000
Re: Reference "Rhodri James" <rhodri@wildebst.org.uk> - 2014-03-05 00:25 +0000
Re: Reference Tim Chase <python.list@tim.thechases.com> - 2014-03-03 15:51 -0600
Re: Reference Jerry Hill <malaclypse2@gmail.com> - 2014-03-03 17:02 -0500
Re: Reference Marko Rauhamaa <marko@pacujo.net> - 2014-03-04 00:22 +0200
Re: Reference Chris Angelico <rosuav@gmail.com> - 2014-03-04 09:27 +1100
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-04 09:33 +1100
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Re: Reference "Rhodri James" <rhodri@wildebst.org.uk> - 2014-03-05 01:08 +0000
Re: Reference Roy Smith <roy@panix.com> - 2014-03-04 21:09 -0500
Re: Reference Rustom Mody <rustompmody@gmail.com> - 2014-03-04 19:36 -0800
Re: Reference Ian Kelly <ian.g.kelly@gmail.com> - 2014-03-04 21:08 -0700
Re: Reference Rustom Mody <rustompmody@gmail.com> - 2014-03-04 20:31 -0800
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Re: Reference alex23 <wuwei23@gmail.com> - 2014-03-05 16:01 +1000
Re: Reference Rustom Mody <rustompmody@gmail.com> - 2014-03-04 22:10 -0800
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-05 17:22 +1100
Re: Reference alex23 <wuwei23@gmail.com> - 2014-03-05 16:28 +1000
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Re: Reference Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-03-05 18:19 +0000
Re: Reference Marko Rauhamaa <marko@pacujo.net> - 2014-03-05 22:23 +0200
Re: Reference Grant Edwards <invalid@invalid.invalid> - 2014-03-05 20:31 +0000
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Re: Reference Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-03-05 21:34 +0000
Re: Reference Terry Reedy <tjreedy@udel.edu> - 2014-03-05 18:00 -0500
Re: Reference Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-03-06 03:01 +0000
Re: Reference Rustom Mody <rustompmody@gmail.com> - 2014-03-04 22:03 -0800
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-05 17:26 +1100
Re: Reference Chris Angelico <rosuav@gmail.com> - 2014-03-05 17:32 +1100
Re: Reference Tim Chase <python.list@tim.thechases.com> - 2014-03-05 08:24 -0600
Re: Reference Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-03-05 18:29 +0000
Re: Reference Marko Rauhamaa <marko@pacujo.net> - 2014-03-05 22:34 +0200
Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-06 08:01 +1100
Re: Reference Marko Rauhamaa <marko@pacujo.net> - 2014-03-05 23:14 +0200
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Re: Reference Chris Angelico <rosuav@gmail.com> - 2014-03-06 11:50 +1100
Re: Reference Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-03-06 17:46 +0000
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Re: Reference Ben Finney <ben+python@benfinney.id.au> - 2014-03-06 08:37 +1100
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Re: Reference Steven D'Aprano <steve@pearwood.info> - 2014-03-04 03:59 +0000
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